Erectile dysfunction (ED) or impotence is the inability to get or keep an erection that is firm enough, or lasts long enough, to have successful sexual intercourse. It can have serious effects on a person's sexual relationship and their self-esteem.
Inflatable penile prostheses may be used to cure or compensate for impotence. Inflatable penile prostheses typically include a pair of inflatable cylinders and a pump. The cylinders are implanted in the corpus cavernosa of the patient, and the pump is implanted in the scrotum of the patient. For some inflatable penile prostheses (i.e., three-piece penile prostheses), a separate fluid reservoir must be implanted in the abdomen of the patient. Alternatively, the fluid reservoir may be combined with the cylinders (i.e., two-piece penile prostheses). Both the three-piece and the two-piece penile inflatable prostheses rely on the transfer of a volume of fluid from the reservoir to the cylinders, to transition the cylinders between deflated and inflated states, which respectively correspond to flaccid and erect penis conditions.
Conventional inflatable penile prosthesis cylinders generally have a uniform wall thickness. The cylinders may expand radially relative to a longitudinal axis of the cylinders when they are inflated. Such girth expansion capability is directly related to the cylinder pressure that can be generated by the patient to overcome the resistance of stretching the wall of the cylinder, or the “stack-up” pressure. The less pressure-generating capability a patient has, the smaller the girth expansion that is possible for each of the cylinders.